During the past 4 years we have studied neurobehavioral performance in a group of 213 healthy men (N-92) and women (N-121) ranging in age from 40-90. They were selected for the absence of disease or other factors which would affect the central nervous system. Even with this strict selection criterion and comparable education levels considerable heterogeneity within age groups was observed for cognitive and psychomotor performance. This heterogeneity of normal aging may be separated into usual aging which results when extrinsic factors heighten the effects of aging alone and successful aging when extrinsic factors play a natural or positive role. The neurobehavioral battery employed consisted of mood and personality questionnaires, Types A Behavior Pattern, locus of control, neuropsychological battery and evoked potentials. This will be repeated when the subjects return with the addition of measures of risk factors associated with cerebrovascular disease, namely, blood pressure, heart disease (see Project 1) diabetes mellitus (fasting blood sugar) hyperlipidemia (e.g., cholesterol, LDL, HDL2, HDL3), alcohol and cigarette use. A neurological examination will include functional measures of cerebrovascular disease with quantitated carotid flow studies using a Doppler Volume Flow Meter. Duplex scanning and oculopneumoplethysmography will determines degree of stenosis and amount of atherosclerotic plaque in the carotid arteries. Whites matter changes in the central nervous system associated with vascular diseases in normal aging will be visualized by MRI of the brain. Results will be graded and correlated with risk factors, carotid flow studies and neurobehavioral performance. Exercise is known to effect circulatory function and mood. Its impact on neurobehavioral performance using the above crotocol will bs examined. In the study populations from Projects 1 and 2, 120 middles age to elderly men will be enrolled in a regular exercise program. Each subject maybe compared to his own baseline besides an appropriately matched sedentary group from men in the longitudinal study. Analysis will be performed to determine which variable or group of variables are the strongest predictor of neurobehavioral performance, namely, presence of risk factors for cerebrovascular disease, functional measures of carotid blood flow or cardiovascular fitness.